I'm curious about something. I have articles submitted to an article writing PPV site, and some of them are also submitted to another PPV site as well as a blog using adsense. The blog links back to the articles on both the other sites. Now I originally did this just to keep all my stuff online in multiple places in case a site goes down. Now I'm curious in terms of SEO, promotion, link build, etc. So far I've continued to promote one of the PPV sites and not promote the others. Will the negatively impact one another somehow if I promote them all? Are they already dragging down one another?